In 2024, I attended the IMSA Battle On The Bricks with the Buckeye Chapter of the BMW Car Club of America – I’ve been a member for 20 years.  The club members got to watch the race from the BMW Performance Center building thats located at Indianapolis Motor Speedway, which has a great observation deck on the roof ideal for taking photos.  At the time, my longest lens was the Canon RF 70-200 f2.8.  And unfortunately it really wasn’t enough lens shooting from that location.  Sure, I got some great shots, but it required more cropping than what I typically like to do.  For 2025, I decided I would use my Canon Professional Services membership (I’ve been a member of CPS for over 25 years now) and get some longer lenses for the race.  The Canon RF 400mm f2.8 seemed like a great choice.  In reality it wasn’t…but I’ll get to that later.

Build and Handling

Let’s get the obvious out of the way: this lens is huge. At just under 6.5 inches wide and 14.5 inches long, it looks like you’ve strapped a small white rocket launcher to your camera. The weight, at around 6.4 pounds, is technically lighter than some of Canon’s older EF telephotos, but after a few hours of shooting on foot, you’ll feel every ounce in your shoulders and forearms.  That front element is s about 163 mm (6.42 inches) across and doesn’t use a lens cap.  Instead, Canon provides a cover that goes over the front element:

Neither does this lens take a conventional screw-on filter – which would be the size of a dinner plate if it did.  Instead, Canon uses the 52mm rear drop-in filter system for practicality.  I didn’t have a 52mm drop-in ND filter unfortunately so I was limited to taking “frozen action” race car photos.

Despite the weight and heft, the balance is surprisingly manageable. The tripod collar is rock solid, and I alternated between shooting on a monopod along the fence line and tripod mounted shots from the roof of the on-track BMW Performance Center. there are three iterations (mark I-III) of the EF 400mm f2.8. Keep in mind this lens is fundamentally the same lens as the EF Mark III counterpart – not a bad thing. The last EF version was announced in 2018, and featured a 25% weight reduction with some additional performance enhancements.

The build quality is pure Canon L-series: weather-sealed, fluorine-coated, and reassuringly durable.  IMSA weekends throw everything at you—dust from the paddock, mist from the jet dryers, sudden showers…it can get rough.  The RF 400mm f2.8 shrugged it all off without drama.

Autofocus Performance

With IMSA cars, autofocus performance is make-or-break. You don’t get second chances when a Porsche 963 or Cadillac V-Series.R rockets out of Turn 1. Here, the RF 400mm f/2.8 is astonishing. The ring-type USM motor locks onto subjects instantly, and with the Dual Pixel AF II system in the R5 Mark II, tracking was sticky and confident even through fencing or when cars darted out of shadows into bright light:

I tested it on a few tricky sequences and the hit rate of tack-sharp frames was staggering. The lens doesn’t just keep up with the speed of the cars; it feels like it anticipates them. I can honestly say it gave me more confidence, knowing the AF would nail the driver’s helmet while the background streaked beautifully.  Obviously the autofocus capabilities of both the Canon R1 and the R5 Mark II I used to test this lens helped.

I do wish I had access to a ND filter so I could have tried some panning shots with the lens.

Image Quality

Let’s be blunt: this lens is the reason people still mortgage their futures for f/2.8 super-telephotos. The sharpness is insane. From wide open at f/2.8 through f/8, the images are clinically crisp. Every decal, every bead of brake dust on the wheels, every heat shimmer in the air behind the cars was rendered with stunning clarity.

Color and contrast are classic Canon: rich, vibrant, with excellent micro-contrast. Flare control was stellar, even shooting head-on into the late afternoon sun as the GTD cars rolled under the Pagoda tower. The Air Sphere Coating and fluorite elements clearly earn their keep.

Image Stabilization

The built-in IS promises up to 5.5 stops of stabilization, and while I wouldn’t push it that far handheld at 400mm (mainly because it wouldn’t take long for my support arm to shake holding this lens) it can make a big difference in practice. I mostly used the lens on either a monopod or tripod but in lens IS is always welcome.

Practicality at the Speedway

Here’s the honest truth: at a place like Indy, a 400mm prime is both perfect and limiting. The RF 400mm f/2.8 demands discipline: you choose your spots, you commit, and you wait for the shot to come to you. When it does, the results are unbeatable.  But it obviously doesn’t work in every situation.  You have three focal length options with this lens – 400mm natively, 560mm with a 1.4 extender, and 800mm with a 2x extender.  Honestly between the limited focal range and the fact that I didn’t have an ND filter that would work with the lens, it ended up being less than an ideal choice for how I wanted to use it.  I ended up getting much better photos with my own EF 100-400 f4.5-5.6.

Final Thoughts

After three days at the 2025 IMSA Battle on the Bricks, I can say the Canon RF 400mm f/2.8 L IS USM is both a luxury and a necessity. Luxury in the sense that most of us don’t need a $12999.00 lens; necessity in the sense that once you use it in the right context, you can’t imagine being without it.

It’s not a walk-around lens. It’s not versatile. It won’t make you a better photographer overnight. But if you’re trackside at Indianapolis, chasing prototypes at dusk as they blast down the straight with the grandstands looming in the background, it’s the one lens that will give you images that stop people in their tracks.  And in motorsports photography, sometimes one frame is worth the entire cost of admission.

Here’s my video supplement to this written photo review: